WO2012011570A1

WO2012011570A1 - Rubber composition and pneumatic tire

Info

Publication number: WO2012011570A1
Application number: PCT/JP2011/066704
Authority: WO
Inventors: 祐子日野原; 西岡　和幸; 馬渕　貴裕
Original assignee: 住友ゴム工業株式会社
Priority date: 2010-07-23
Filing date: 2011-07-22
Publication date: 2012-01-26
Also published as: CN103003347A; KR20130093588A; EP2597119B1; KR101824281B1; BR112012033814A2; JP5762412B2; JPWO2012011570A1; EP2597119A1; RU2012156027A; US9139719B2; RU2568475C2; US20130090422A1; EP2597119A4; CN103003347B

Abstract

Disclosed is a rubber composition that improves fuel economy, wet grip performance, and wear resistance in a balanced manner. Also disclosed is a pneumatic tire using said rubber composition. By mass, said rubber composition contains 100 parts of a rubber component and 5-150 parts silica. At least 5% of the mass of the rubber component comprises a conjugated diene copolymer that has: a constituent unit based on a conjugated diene; and a constituent unit represented by formula (I). At least one end of said conjugated diene copolymer is modified by a compound containing a group represented by formula (II).

Description

Rubber composition and pneumatic tire

The present invention relates to a rubber composition and a pneumatic tire produced using the rubber composition.

In recent years, due to increasing interest in environmental issues, there has been a strong demand for lower fuel consumption for automobiles, and rubber compositions used for automobile tires are also required to have excellent fuel efficiency. . As rubber compositions for automobile tires, rubber compositions containing conjugated diene polymers such as polybutadiene and butadiene-styrene copolymers and fillers such as carbon black and silica are used.

As a method for improving fuel economy, for example, Patent Document 1 proposes a method using a diene rubber modified with an organosilicon compound containing an amino group and an alkoxy group. However, in recent years, further improvement in fuel efficiency has been demanded. In addition, the performance required for rubber compositions for automobile tires includes wet grip performance and wear resistance, but these performances are generally in contradiction to low fuel consumption. It was difficult to obtain a high dimension and good balance.

JP 2000-344955 A

An object of the present invention is to solve the above-mentioned problems and to provide a rubber composition that can improve fuel economy, wet grip performance, and wear resistance in a well-balanced manner, and a pneumatic tire using the same.

The present invention is a conjugated diene polymer containing a rubber component and silica and having a structural unit based on a conjugated diene and a structural unit represented by the following formula (I) in 100% by mass of the rubber component. The content of the conjugated diene polymer obtained by modifying at least one end of the polymer with a compound having a group represented by the following formula (II) is 5% by mass or more, and the silica with respect to 100 parts by mass of the rubber component The present invention relates to a rubber composition having a content of 5 to 150 parts by mass.

[Wherein, X ¹ , X ² and X ³ each independently represent a group represented by the following formula (Ia), a hydroxyl group, a hydrocarbyl group or a substituted hydrocarbyl group, and at least ^one of X ¹ , X ² and X ³ One is a group or a hydroxyl group represented by the following formula (Ia). ]

[Wherein, R ¹ and R ² each independently represent a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having a carbon number of 1-6, a silyl group, or a substituted silyl group, R ¹ and R ² may be bonded to form a ring structure with the nitrogen atom. ]

[Wherein, m represents an integer of 1 to 11, and A represents a functional group having a nitrogen atom. ]

R ¹ and R ^{2 in} formula (Ia) are preferably hydrocarbyl groups having 1 to 6 carbon atoms.

^Two of X ¹ , X ² and X ^{3 in} the formula (I) are preferably a group or a hydroxyl group represented by the formula (Ia).

The compound having a group represented by the formula (II) is preferably a compound represented by the following formula (III).

[Wherein n represents an integer of 0 to 10, R ³ represents a hydrocarbyl group having 1 to 5 carbon atoms, and R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represents a hydrogen atom, A hydrocarbyl group having 1 to 5 carbon atoms, a substituted hydrocarbyl group having 1 to 5 carbon atoms, or a hydrocarbyloxy group having 1 to 5 carbon atoms, and a plurality of R ⁴ and R ⁵ are present. R ⁴ and a plurality of R ⁵ may be the same or different, and R ⁸ and R ⁹ are each independently at least one selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. Represents a group having 1 to 6 carbon atoms which may have an atom, R ⁸ and R ⁹ may combine to form a ring structure with a nitrogen atom, and R ⁸ and R ⁹ It may be the same group bonded by a double bond ]

One of R ⁶ and R ⁷ in formula (III) is preferably a hydrogen atom.

The vinyl bond content of the conjugated diene polymer is preferably 10 mol% or more and 80 mol% or less, with the content of the constituent unit based on the conjugated diene being 100 mol%.

The rubber composition preferably contains natural rubber and / or butadiene rubber.

The silica preferably has a nitrogen adsorption specific surface area of 40 to 400 m ² / g.

The rubber composition is preferably used as a tread rubber composition.

The present invention also relates to a pneumatic tire produced using the rubber composition.

According to the present invention, since it is a rubber composition containing a specific conjugated diene polymer and silica, it is possible to provide a pneumatic tire with improved fuel economy, wet grip performance and wear resistance in a well-balanced manner. .

The rubber composition of the present invention is a conjugated diene polymer having a structural unit based on a conjugated diene and a structural unit represented by the following formula (I), and has a group represented by the following formula (II): A conjugated diene polymer in which at least one end of the polymer is modified with a compound and silica.

Examples of the conjugated diene based on the conjugated diene include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 1,3-hexadiene, and the like. These may be one type or two or more types. From the viewpoint of availability, 1,3-butadiene and isoprene are preferred.

X ¹ , X ² and X ³ in formula (I) of the structural unit represented by formula (I) each independently represent a group represented by formula (Ia), a hydroxyl group, a hydrocarbyl group or a substituted hydrocarbyl group. , X ¹ , X ² and X ³ are a group represented by the formula (Ia) or a hydroxyl group.

R ¹ and R ² of formula (Ia) represent each independently, a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having a carbon number of 1-6, a silyl group, or a substituted silyl group, R ¹ And R ² may be bonded together to form a ring structure together with the nitrogen atom.

As used herein, a hydrocarbyl group represents a hydrocarbon residue. Here, the hydrocarbon residue represents a monovalent group obtained by removing hydrogen from a hydrocarbon. A substituted hydrocarbyl group represents a group in which one or more hydrogen atoms of a hydrocarbon residue are substituted with a substituent. The hydrocarbyloxy group represents a group in which a hydrogen atom of a hydroxyl group is substituted with a hydrocarbyl group, and the substituted hydrocarbyloxy group represents a group in which one or more hydrogen atoms of the hydrocarbyloxy group are substituted with a substituent. The substituted silyl group represents a group in which one or more hydrogen atoms of the silyl group are substituted with a substituent.

Examples of the hydrocarbyl group having 1 to 6 carbon atoms in R ¹ and R ² include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n- Examples thereof include alkyl groups such as pentyl group, neopentyl group, isopentyl group and n-hexyl group; cycloalkyl groups such as cyclohexyl group; phenyl groups and the like.

The substituted hydrocarbyl group having 1 to 6 carbon atoms in R ¹ and R ² is at least one group selected from the group consisting of a group having a nitrogen atom, a group having an oxygen atom, and a group having a silicon atom. The substituted hydrocarbyl group which has as a substituent can be mentioned. Examples of the group having a nitrogen atom group as a substituent include dialkylaminoalkyl groups such as a dimethylaminoethyl group and a diethylaminoethyl group. Examples of the group having an oxygen atom group as a substituent include methoxymethyl Group, methoxyethyl group, ethoxymethyl group, alkoxyalkyl group such as ethoxyethyl group, and the like. As the group having a silicon atom group as a substituent, a trialkylsilylalkyl group such as trimethylsilylmethyl group, etc. Can be mentioned.

Examples of the substituted silyl group for R ¹ and R ² include trialkylsilyl groups such as a trimethylsilyl group, a triethylsilyl group, and a t-butyldimethylsilyl group.

The group to which R ¹ and R ² are bonded is a divalent group having 1 to 12 carbon atoms which may have at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. Groups. For example, an alkylene group such as a trimethylene group, a tetramethylene group, a pentamethylene group, or a hexamethylene group; an oxydialkylene group such as an oxydiethylene group or an oxydipropylene group; —CH ₂ CH ₂ —NH—CH ₂ — And a nitrogen-containing group such as a group represented by —CH ₂ CH ₂ —N═CH—.

The group to which R ¹ and R ² are bonded is preferably a nitrogen-containing group, a group represented by —CH ₂ CH ₂ —NH—CH ₂ —, a group represented by —CH ₂ CH ₂ —N═CH—. Is more preferable.

The hydrocarbyl group of R ¹ and R ² is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group, an ethyl group, an n-propyl group, or an n-butyl group. And the group n-butyl is particularly preferred. The substituted hydrocarbyl group for R ¹ and R ² is preferably an alkoxyalkyl group, more preferably an alkoxyalkyl group having 1 to 4 carbon atoms. The substituted silyl group for R ¹ and R ² is preferably a trialkylsilyl group, and more preferably a trimethylsilyl group.

R ¹ and R ² are preferably an alkyl group, an alkoxyalkyl group, a substituted silyl group, or a nitrogen-containing group to which R ¹ and R ² are bonded, more preferably an alkyl group, still more preferably carbon. It is an alkyl group having 1 to 4 atoms, and more preferably a methyl group, an ethyl group, an n-propyl group, or an n-butyl group.

Examples of the group represented by the formula (Ia) include an acyclic amino group and a cyclic amino group.
Examples of the acyclic amino group include dimethylamino group, diethylamino group, di (n-propyl) amino group, di (isopropyl) amino group, di (n-butyl) amino group, di (sec-butyl) amino group, di ( dialkylamino groups such as tert-butyl) amino group, di (neopentyl) amino group, ethylmethylamino group; di (methoxymethyl) amino group, di (methoxyethyl) amino group, di (ethoxymethyl) amino group, di ( And di (alkoxyalkyl) amino groups such as ethoxyethyl) amino group; and di (trialkylsilyl) amino groups such as di (trimethylsilyl) amino group and di (t-butyldimethylsilyl) amino group.

Examples of the cyclic amino group include 1-pyrrolidinyl group, 1-piperidino group, 1-hexamethyleneimino group, 1-heptamethyleneimino group, 1-octamethyleneimino group, 1-decamethyleneimino group, 1-dodecamethyleneimino group. Mention may be made of 1-polymethyleneimino groups such as groups. Examples of the cyclic amino group include 1-imidazolyl group, 4,5-dihydro-1-imidazolyl group, 1-imidazolidinyl group, 1-piperazinyl group, morpholino group and the like.

The group represented by the formula (Ia) is preferably an acyclic amino group, more preferably a dialkylamino group, and still more preferably a carbon atom number of 1 to 1, in view of economy and availability. A dialkylamino group substituted with 4 alkyl groups, and more preferably a dimethylamino group, a diethylamino group, a di (n-propyl) amino group, or a di (n-butyl) amino group.

Examples of the hydrocarbyl group of X ¹ , X ² and X ^{3 in} the formula (I) include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group. The group can be mentioned. In addition, examples of the substituted hydrocarbyl group include alkoxyalkyl groups such as a methoxymethyl group, an ethoxymethyl group, a methoxyethyl group, and an ethoxyethyl group.

The hydrocarbyl group of X ¹ , X ² and X ³ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group or an ethyl group. In addition, the substituted hydrocarbyl group of X ¹ , X ² and X ³ is preferably an alkoxyalkyl group, more preferably an alkoxyalkyl group having 1 to 4 carbon atoms.

The hydrocarbyl group and substituted hydrocarbyl group of X ¹ , X ² and X ³ are preferably an alkyl group or an alkoxyalkyl group, more preferably an alkyl group having 1 to 4 carbon atoms or a carbon atom number of 1 An alkoxyalkyl group having 4 to 4, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group or an ethyl group.

At least one of X ¹ , X ² and X ^{3 in} the formula (I) is a group or a hydroxyl group represented by the formula (Ia). Preferably, two or more of X ¹ , X ² and X ³ are a group or a hydroxyl group represented by the formula (Ia), more preferably ^{two of} X ¹ , X ² and X ³ are represented by the formula (Ia ) Or a hydroxyl group. Moreover, it is preferable that at least one of X ¹ , X ^2, and X ³ is a hydroxyl group from the viewpoint that low fuel consumption, wet grip performance, and wear resistance can be obtained in a high-order and well-balanced manner, and X ¹ , X ² and It is more preferable that two or more of X ³ are hydroxyl groups, and it is still more preferable that ^{two of} X ¹ , X ² and X ³ are hydroxyl groups.

From the viewpoint of improving fuel economy, wet grip performance and wear resistance in a well-balanced manner, as the structural unit represented by the formula (I), ^{two of} X ¹ , X ² and X ³ are acyclic amino groups or hydroxyl groups. A structural unit is preferred. As the structural unit in which ^{two of} X ¹ , X ² and X ³ are acyclic amino groups, bis (dialkylamino) alkylvinylsilane units are preferred, bis (dimethylamino) methylvinylsilane units, bis (diethylamino) methylvinylsilane units, Bis (di (n-propyl) amino) methylvinylsilane units and bis (di (n-butyl) amino) methylvinylsilane units are more preferred. As the structural unit in which two of X ¹ , X ² and X ³ are hydroxyl groups, a dihydroxyalkylvinylsilane unit is preferable, and a dihydroxymethylvinylsilane unit is more preferable.

The content of the structural unit represented by the formula (I) in the conjugated diene polymer is preferably 0 per unit mass of the polymer from the viewpoint of improving fuel economy, wet grip performance and wear resistance in a balanced manner. It is 0.001 mmol / g polymer or more and 0.1 mmol / g polymer or less. More preferably, it is 0.002 mmol / g polymer or more and 0.07 mmol / g polymer or less. More preferably, it is 0.003 mmol / g polymer or more and 0.05 mmol / g polymer or less. *

The conjugated diene polymer is a polymer obtained by modifying at least one end of a polymer with a compound having a group represented by the following formula (II).

m represents an integer of 1 to 11. From the viewpoint of improving fuel efficiency, it is preferably 1 or more, and from the viewpoint of improving economy during production, it is preferably 4 or less. A is a functional group having a nitrogen atom, and examples thereof include an amino group, an isocyano group, a cyano group, a pyridyl group, a piperidyl group, a pyrazinyl group, and a morpholino group.

Examples of the compound having a group represented by the formula (II) include a compound represented by the following formula (III).

N in the formula (III) represents an integer of 0 to 10. From the viewpoint of improving economy, it is preferably 3 or less, more preferably 0.

R ^{3 in} formula (III) represents a hydrocarbyl group having 1 to 5 carbon atoms. Examples of the hydrocarbyl group of R ³ include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and t-butyl group.

The hydrocarbyl group for R ³ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group or an ethyl group.

R ⁴ to R ^{7 in} formula (III) are each independently a hydrogen atom, a hydrocarbyl group having 1 to 5 carbon atoms, a substituted hydrocarbyl group having 1 to 5 carbon atoms, or a group having 1 to 5 carbon atoms. represent hydrocarbyl group, when R ⁴ and R ⁵ are a plurality, the R ⁵ to R is ⁴ and a plurality of plurality of may be different even in the same, respectively.

Examples of the hydrocarbyl group of R ⁴ to R ⁷ include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and t-butyl group.

Examples of the substituted hydrocarbyl group of R ⁴ to R ⁷ include a substituted hydrocarbyl group having as a substituent at least one group selected from the group consisting of a group having a nitrogen atom and a group having an oxygen atom. Examples of the group having a nitrogen atom group as a substituent include dialkylaminoalkyl groups such as a dimethylaminoethyl group and a diethylaminoethyl group. Examples of the group having an oxygen atom group as a substituent include methoxymethyl And alkoxyalkyl groups such as a methoxyethyl group, an ethoxymethyl group, and an ethoxyethyl group.

Examples of the hydrocarbyloxy group of R ⁴ to R ⁷ include alkoxy groups such as a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, and a t-butoxy group. .

The hydrocarbyl group of R ⁴ to R ⁷ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group or an ethyl group.

The substituted hydrocarbyl group of R ⁴ to R ⁷ is preferably an alkoxyalkyl group, more preferably an alkoxyalkyl group having 1 to 4 carbon atoms, and further preferably a methoxymethyl group or an ethoxyethyl group. .

The hydrocarbyloxy group of R ⁴ to R ⁷ is preferably an alkoxy group, more preferably an alkoxy group having 1 to 3 carbon atoms, and still more preferably a methoxy group or an ethoxy group.

From the viewpoint of improving fuel economy, wet grip performance and wear resistance in a well-balanced manner and economy, it is preferable that one of R ⁶ and R ⁷ is a hydrogen atom. More preferably, one of R ⁶ and R ⁷ is a hydrogen atom, and the other is an alkyl group or an alkoxy group. More preferably, one of R ⁶ and R ⁷ is a hydrogen atom, and the other is an alkoxy group. Particularly preferred are a methoxy group and an ethoxy group.

R ⁸ and R ^{9 in} formula (III) each independently have 1 to 6 carbon atoms which may have at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. R ⁸ and R ⁹ may be bonded to form a ring structure together with the nitrogen atom, and R ⁸ and R ⁹ may be the same group bonded to nitrogen by a double bond.

Examples of R ⁸ and R ^{9 in} formula (III) include a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having 1 to 6 carbon atoms, and a substituted silyl group.

Examples of the hydrocarbyl group of R ⁸ and R ⁹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, neopentyl group, and isopentyl group. And alkyl groups such as n-hexyl group; cycloalkyl groups such as cyclohexyl group; phenyl groups and the like.

The substituted hydrocarbyl group of R ⁸ and R ^{9 is} a substituted hydrocarbyl group having as a substituent at least one group selected from the group consisting of a group having a nitrogen atom, a group having an oxygen atom and a group having a silicon atom. Can be mentioned. Examples of the group having a nitrogen atom group as a substituent include dialkylaminoalkyl groups such as a dimethylaminoethyl group and a diethylaminoethyl group. Examples of the group having an oxygen atom group as a substituent include methoxymethyl Group, alkoxyalkyl group such as methoxyethyl group, ethoxymethyl group, ethoxyethyl group; alkylene oxide group such as epoxy group, tetrahydrofuranyl group; alkylene oxide alkyl group such as glycidyl group, tetrahydrofurfuryl group, etc. Examples of the group having a group having a silicon atom as a substituent include a trialkylsilylalkyl group such as a trimethylsilylmethyl group.
In the present specification, the alkylene oxide group represents a monovalent group obtained by removing a hydrogen atom from a ring of a cyclic ether compound. The alkylene oxide alkyl group represents a group in which one or more hydrogen atoms of the alkyl group are substituted with an alkylene oxide group.

Examples of the substituted silyl group of R ⁸ and R ⁹ include trialkylsilyl groups such as trimethylsilyl group, triethylsilyl group and t-butyldimethylsilyl group; trialkoxysilyl groups such as trimethoxysilyl group.

The group to which R ⁸ and R ⁹ are bonded is a divalent group having 2 to 12 carbon atoms that may have at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. Groups. For example, an alkylene group such as a trimethylene group, a tetramethylene group, a pentamethylene group, or a hexamethylene group; an oxydialkylene group such as an oxydiethylene group or an oxydipropylene group; —CH ₂ CH ₂ —NH—CH ₂ — And a nitrogen-containing group such as a group represented by —CH ₂ CH ₂ —N═CH—.

The group to which R ⁸ and R ⁹ are bonded is preferably a nitrogen-containing group, a group represented by —CH ₂ CH ₂ —NH—CH ₂ —, a group represented by —CH ₂ CH ₂ —N═CH—. Is more preferable.

As the same group bonded to the nitrogen of R ⁸ and R ^{9 by} a double bond, the number of carbon atoms optionally having at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom 2 to 12 divalent groups. Examples thereof include an ethylidene group, 1-methylpropylidene group, 1,3-dimethylbutylidene group, 1-methylethylidene group, 4-N, N-dimethylaminobenzylidene group.

The hydrocarbyl group of R ⁸ and R ⁹ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, still more preferably a methyl group, an ethyl group, or an n-propyl group. N-butyl group, more preferably a methyl group or an ethyl group. The substituted hydrocarbyl group for R ⁸ and R ⁹ is preferably an alkoxyalkyl group, an alkylene oxide group, or an alkylene oxide alkyl group. The substituted silyl group for R ⁸ and R ⁹ is preferably a trialkylsilyl group or a trialkoxysilyl group, more preferably a trialkylsilyl group, still more preferably a trimethylsilyl group or a triethylsilyl group. .

R ⁸ and R ⁹ are preferably an alkyl group, an alkoxyalkyl group, a substituted silyl group, or a nitrogen-containing group to which R ⁸ and R ⁹ are bonded, and more preferably an alkyl group having 1 to 4 carbon atoms. More preferred are a methyl group, an ethyl group, an n-propyl group, and an n-butyl group, and even more preferred are a methyl group and an ethyl group.

Examples of the amino group in which R ⁸ and R ⁹ are bonded to a nitrogen atom include an acyclic amino group and a cyclic amino group.
Examples of the acyclic amino group include dimethylamino group, diethylamino group, di (n-propyl) amino group, di (isopropyl) amino group, di (n-butyl) amino group, di (sec-butyl) amino group, di ( dialkylamino groups such as tert-butyl) amino group, di (neopentyl) amino group, ethylmethylamino group; di (methoxymethyl) amino group, di (methoxyethyl) amino group, di (ethoxymethyl) amino group, di ( And di (alkoxyalkyl) amino groups such as ethoxyethyl) amino group; and di (trialkylsilyl) amino groups such as di (trimethylsilyl) amino group and di (t-butyldimethylsilyl) amino group. In addition, di (alkylene oxide) amino groups such as di (epoxy) amino groups and di (tetrahydrofuranyl) amino groups; di (alkylene oxide alkyl) amino groups such as di (glycidyl) amino groups and di (tetrahydrofurfuryl) amino groups The group can be mentioned. Furthermore, an ethylideneamino group, a 1-methylpropylideneamino group, a 1,3-dimethylbutylideneamino group, a 1-methylethylideneamino group, a 4-N, N-dimethylaminobenzylideneamino group and the like can also be mentioned.

The amino group in which R ⁸ and R ⁹ are bonded to the nitrogen atom is preferably an acyclic amino group from the viewpoint of low fuel consumption, wet grip performance, wear resistance, long-term stability and availability of the compound, and more A dialkylamino group is preferable, and a dimethylamino group and a diethylamino group are more preferable.

Examples of the compound represented by the formula (III) include N, N-dialkyl-substituted carboxylic acid amide dialkyl acetal compounds.

As the N, N-dialkyl-substituted carboxylic acid amide dialkyl acetal compound,
N, N-dimethylformamide dimethyl acetal, N, N-diethylformamide dimethyl acetal, N, N-di (n-propyl) formamide dimethyl acetal,
N, N-dimethylformamide diethyl acetal, N, N-diethylformamide diethyl acetal, N, N-di (n-propyl) formamide diethyl acetal,
N, N-dialkylformamide dialkyl acetals such as N, N-dimethylformamide ethyl methyl acetal, N, N-diethylformamide ethyl methyl acetal, N, N-di (n-propyl) formamide ethyl methyl acetal;

N, N-dimethylacetamide dimethyl acetal, N, N-diethylacetamide dimethyl acetal, N, N-di (n-propyl) acetamide dimethyl acetal,
N, N-dimethylacetamide diethyl acetal, N, N-diethylacetamide diethyl acetal, N, N-di (n-propyl) acetamide diethyl acetal,
N, N-dialkylacetamido dialkyl acetals such as N, N-dimethylacetamidoethyl methyl acetal, N, N-diethylacetamidoethyl methyl acetal, N, N-di (n-propyl) acetamidoethyl methyl acetal;

N, N-dimethylpropionamide dimethyl acetal, N, N-diethylpropionamide dimethyl acetal, N, N-di (n-propyl) propionamide dimethyl acetal,
N, N-dimethylpropionamide diethyl acetal, N, N-diethylpropionamide diethyl acetal, N, N-di (n-propyl) propionamide diethyl acetal,
N, N-dimethylpropionamidoethyl methyl acetal, N, N-diethylpropionamidoethyl methyl acetal, N, N-di (n-propyl) propionamidoethyl methyl acetal Can be mentioned.

Among these, from the viewpoint of improving the fuel efficiency, wet grip performance and wear resistance in a balanced manner,
N, N-dialkylformamide dialkyl acetal,
More preferably,
N, N-dimethylformamide dimethyl acetal,
N, N-diethylformamide dimethyl acetal,
N, N-dimethylformamide diethyl acetal,
N, N-diethylformamide diethyl acetal.

The conjugated diene polymer may have a constituent unit based on another monomer in addition to the constituent unit based on the conjugated diene (conjugated diene unit). Examples of the other monomer include aromatic vinyl, vinyl nitrile, and unsaturated carboxylic acid ester. Examples of the aromatic vinyl include styrene, α-methylstyrene, vinyl toluene, vinyl naphthalene, divinyl benzene, trivinyl benzene, and divinyl naphthalene. Examples of the vinyl nitrile include acrylonitrile, and examples of the unsaturated carboxylic acid ester include methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate. Among these, aromatic vinyl is preferable, and styrene is more preferable.

The conjugated diene polymer preferably has a structural unit based on aromatic vinyl (aromatic vinyl unit) from the viewpoint of wear resistance. The content of the aromatic vinyl unit is preferably a conjugated diene unit. And the total amount of aromatic vinyl units is 100% by mass, preferably 10% by mass or more (conjugated diene unit content is 90% by mass or less), more preferably 15% by mass or more (conjugate diene unit content) Is 85% by mass or less). Further, from the viewpoint of low fuel consumption, the content of the aromatic vinyl unit is preferably 50% by mass or less (the content of the conjugated diene unit is 50% by mass or more), more preferably 45% by mass or less (conjugated diene). The unit content is 55% by mass or more).

The vinyl bond content of the conjugated diene polymer is preferably 80 mol% or less, more preferably 70 mol% or less from the viewpoint of fuel efficiency, with the content of the conjugated diene unit being 100 mol%. Moreover, from a viewpoint of wet grip performance, Preferably it is 10 mol% or more, More preferably, it is 15 mol% or more, More preferably, it is 20 mol% or more, Most preferably, it is 40 mol% or more. The vinyl bond amount is determined from the absorption intensity in the vicinity of 910 cm ^−1, which is the absorption peak of the vinyl group, by infrared spectroscopy.

The molecular weight distribution of the conjugated diene polymer is preferably 1 to 5 and more preferably 1 to 2 from the viewpoint of low fuel consumption. The molecular weight distribution is obtained by measuring the number average molecular weight (Mn) and the weight average molecular weight (Mw) by gel permeation chromatography (GPC) method and dividing Mw by Mn.

As a suitable manufacturing method of the said conjugated diene type polymer, the manufacturing method which has the following process A and B can be mentioned.
(Step A): In a hydrocarbon solvent, a monomer containing a conjugated diene and a vinyl compound represented by the following formula (IV) is polymerized with an alkali metal catalyst, and a monomer unit based on the conjugated diene and A step of obtaining a polymer having an alkali metal derived from the catalyst at at least one end of a polymer chain having a monomer unit based on a vinyl compound represented by the formula (IV).

[Wherein, X ⁴ , X ⁵ and X ⁶ each independently represent a group represented by the following formula (IVa), a hydrocarbyl group or a substituted hydrocarbyl group, wherein at least one of X ⁴ , X ⁵ and X ⁶ is And a group represented by the following formula (IVa). ]

^{Wherein, R 10} and ^{R 11} each independently represent a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having a carbon number of 1-6, a silyl group, or a substituted silyl ^{group, R 10} and R ¹¹ may be bonded to form a ring structure with the nitrogen atom. ]
(Step B): A step of reacting the polymer obtained in Step A with a compound having a group represented by the following formula (II).

Examples of the alkali metal catalyst used in (Step A) include an alkali metal, an organic alkali metal compound, a complex of an alkali metal and a polar compound, an oligomer having an alkali metal, and the like. Examples of the alkali metal include lithium, sodium, potassium, rubidium, cesium and the like. Examples of the organic alkali metal compound include ethyl lithium, n-propyl lithium, iso-propyl lithium, n-butyl lithium, sec-butyl lithium, t-octyl lithium, n-decyl lithium, phenyl lithium, 2-naphthyl lithium, 2 -Butylphenyllithium, 4-phenylbutyllithium, cyclohexyllithium, 4-cyclopentyllithium, dimethylaminopropyllithium, diethylaminopropyllithium, t-butyldimethylsiloxypropyllithium, N-morpholinopropyllithium, lithium hexamethyleneimide, lithium pyrrole Zido, lithium piperidide, lithium heptamethylene imide, lithium dodecamethylene imide, 1,4-dilithio-2-butene, sodium naphthalenide, sodium Bifenirido, such as potassium napthalenide can be mentioned. Examples of the complex of alkali metal and polar compound include potassium-tetrahydrofuran complex and potassium-diethoxyethane complex. Examples of the oligomer having alkali metal include sodium salt of α-methylstyrene tetramer. Can do. Among these, an organic lithium compound or an organic sodium compound is preferable, and an organic lithium compound or an organic sodium compound having 2 to 20 carbon atoms is more preferable.

The hydrocarbon solvent used in (Step A) is a solvent that does not deactivate the organic alkali metal compound catalyst, and examples thereof include aliphatic hydrocarbons, aromatic hydrocarbons, and alicyclic hydrocarbons. Examples of the aliphatic hydrocarbon include propane, n-butane, iso-butane, n-pentane, iso-pentane, n-hexane, propene, 1-butene, iso-butene, trans-2-butene, cis-2- Examples include butene, 1-pentene, 2-pentene, 1-hexene, and 2-hexene. In addition, examples of the aromatic hydrocarbon include benzene, toluene, xylene, and ethylbenzene, and examples of the alicyclic hydrocarbon include cyclopentane and cyclohexane. These may be used alone or in combination of two or more. Of these, hydrocarbons having 2 to 12 carbon atoms are preferable.

In (Step A), a monomer containing a conjugated diene and a vinyl compound represented by formula (IV) is polymerized, and a conjugated diene polymer having an alkali metal derived from the above-mentioned alkali metal catalyst at the polymer chain end. Manufacturing. Examples of the conjugated diene include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, and 1,3-hexadiene. Used in combination of more than one species. Of these, 1,3-butadiene and isoprene are preferred from the viewpoint of availability.

X ⁴ , X ⁵ and X ⁶ in the formula (IV) each independently represent a group represented by the formula (IVa), a hydrocarbyl group or a substituted hydrocarbyl group, and at least one of X ⁴ , X ⁵ and X ⁶ Is a group represented by the formula (IVa).

^{R 10} and ^{R 11} of formula (IVa) represents each independently a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having a carbon number of 1-6, a silyl group, or a substituted silyl ^{group, R 10} And R ¹¹ may be bonded together to form a ring structure together with the nitrogen atom.

Examples of the hydrocarbyl group having 1 to 6 carbon atoms of R ¹⁰ and R ¹¹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n- Examples thereof include alkyl groups such as pentyl group, neopentyl group, isopentyl group and n-hexyl group; cycloalkyl groups such as cyclohexyl group; phenyl groups and the like.

The substituted hydrocarbyl group having 1 to 6 carbon atoms of R ¹⁰ and R ¹¹ is at least one group selected from the group consisting of a group having a nitrogen atom, a group having an oxygen atom, and a group having a silicon atom. The substituted hydrocarbyl group which has as a substituent can be mentioned. Examples of the group having a nitrogen atom group as a substituent include dialkylaminoalkyl groups such as a dimethylaminoethyl group and a diethylaminoethyl group. Examples of the group having an oxygen atom group as a substituent include methoxymethyl Group, methoxyethyl group, ethoxymethyl group, alkoxyalkyl group such as ethoxyethyl group, and the like. As the group having a silicon atom group as a substituent, a trialkylsilylalkyl group such as trimethylsilylmethyl group, etc. Can be mentioned.

Examples of the substituted silyl group of R ¹⁰ and R ¹¹ include trialkylsilyl groups such as a trimethylsilyl group, a triethylsilyl group, and a t-butyldimethylsilyl group.

The group to which R ¹⁰ and R ¹¹ are bonded is a divalent group having 1 to 12 carbon atoms that may have at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. Groups. For example, an alkylene group such as a trimethylene group, a tetramethylene group, a pentamethylene group, or a hexamethylene group; an oxydialkylene group such as an oxydiethylene group or an oxydipropylene group; —CH ₂ CH ₂ —NH—CH ₂ — And a nitrogen-containing group such as a group represented by —CH ₂ CH ₂ —N═CH—.

The group to which R ¹⁰ and R ¹¹ are bonded is preferably a nitrogen-containing group, a group represented by —CH ₂ CH ₂ —NH—CH ₂ —, a group represented by —CH ₂ CH ₂ —N═CH—. Is more preferable.

The hydrocarbyl group of R ¹⁰ and R ¹¹ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group, an ethyl group, an n-propyl group, or an n-butyl group, And the group n-butyl is particularly preferred. The substituted hydrocarbyl group for R ¹⁰ and R ¹¹ is preferably an alkoxyalkyl group, more preferably an alkoxyalkyl group having 1 to 4 carbon atoms. The substituted silyl group for R ¹⁰ and R ¹¹ is preferably a trialkylsilyl group, and more preferably a trimethylsilyl group.

R ¹⁰ and R ¹¹ are preferably an alkyl group, an alkoxyalkyl group, a substituted silyl group, or a nitrogen-containing group to which R ¹⁰ and R ¹¹ are bonded, more preferably an alkyl group, still more preferably carbon. It is an alkyl group having 1 to 4 atoms, and more preferably a methyl group, an ethyl group, an n-propyl group, or an n-butyl group.

Examples of the group represented by the formula (IVa) include an acyclic amino group and a cyclic amino group.
Examples of the acyclic amino group include dimethylamino group, diethylamino group, di (n-propyl) amino group, di (isopropyl) amino group, di (n-butyl) amino group, di (sec-butyl) amino group, di ( dialkylamino groups such as tert-butyl) amino group, di (neopentyl) amino group, ethylmethylamino group; di (methoxymethyl) amino group, di (methoxyethyl) amino group, di (ethoxymethyl) amino group, di ( And di (alkoxyalkyl) amino groups such as ethoxyethyl) amino group; and di (trialkylsilyl) amino groups such as di (trimethylsilyl) amino group and di (t-butyldimethylsilyl) amino group.

The group represented by the formula (IVa) is preferably an acyclic amino group, more preferably a dialkylamino group, and still more preferably a carbon atom number of 1 to 1, in view of economy and availability. A dialkylamino group substituted with 4 alkyl groups, and more preferably a dimethylamino group, a diethylamino group, a di (n-propyl) amino group, or a di (n-butyl) amino group.

Examples of the hydrocarbyl group of X ⁴ , X ⁵ and X ^{6 in} the formula (IV) include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group. The group can be mentioned. In addition, examples of the substituted hydrocarbyl group include alkoxyalkyl groups such as a methoxymethyl group, an ethoxymethyl group, a methoxyethyl group, and an ethoxyethyl group.

The hydrocarbyl group of X ⁴ , X ⁵ and X ⁶ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group or an ethyl group. In addition, the substituted hydrocarbyl group of X ⁴ , X ⁵ and X ⁶ is preferably an alkoxyalkyl group, more preferably an alkoxyalkyl group having 1 to 4 carbon atoms.

The hydrocarbyl group and substituted hydrocarbyl group of X ⁴ , X ⁵ and X ⁶ are preferably an alkyl group or an alkoxyalkyl group, more preferably an alkyl group having 1 to 4 carbon atoms or a carbon atom number of 1 An alkoxyalkyl group having 4 to 4, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group or an ethyl group.

At least one of X ⁴ , X ⁵ and X ^{6 in} the formula (IV) is a group represented by the formula (IVa). Preferably, two or more of X ⁴ , X ⁵ and X ⁶ are groups represented by formula (IVa), more preferably two of X ⁴ , X ⁵ and X ⁶ are represented by formula (IVa) It is a group represented.

As the vinyl compound represented by the formula (IV) used in (Step A), one of X ⁴ , X ⁵ and X ⁶ is an acyclic amino group represented by the formula (IVa), and two are hydrocarbyl groups. Alternatively, examples of the compound that is a substituted hydrocarbyl group include (dialkylamino) dialkylvinylsilane, {di (trialkylsilyl) amino} dialkylvinylsilane, (dialkylamino) dialkoxyalkylvinylsilane, and the like.
(Dialkylamino) dialkylvinylsilanes include (dimethylamino) dimethylvinylsilane, (ethylmethylamino) dimethylvinylsilane, (diethylamino) dimethylvinylsilane, (ethyl-n-propylamino) dimethylvinylsilane, (ethylisopropylamino) dimethylvinylsilane, ( Di (n-propyl) amino) dimethylvinylsilane, (diisopropylamino) dimethylvinylsilane, (n-butyl-n-propylamino) dimethylvinylsilane, (di (n-butyl) amino) dimethylvinylsilane,
(Dimethylamino) diethylvinylsilane, (ethylmethylamino) diethylvinylsilane, (diethylamino) diethylvinylsilane, (ethyl-n-propylamino) diethylvinylsilane, (ethylisopropylamino) diethylvinylsilane, (di (n-propyl) amino) diethyl Vinylsilane, (diisopropylamino) diethylvinylsilane, (n-butyl-n-propylamino) diethylvinylsilane, (di (n-butyl) amino) diethylvinylsilane,
(Dimethylamino) dipropylvinylsilane, (ethylmethylamino) dipropylvinylsilane, (diethylamino) dipropylvinylsilane, (ethyl-n-propylamino) dipropylvinylsilane, (ethylisopropylamino) dipropylvinylsilane, (di (n- Propyl) amino) dipropylvinylsilane, (diisopropylamino) dipropylvinylsilane, (n-butyl-n-propylamino) dipropylvinylsilane, (di (n-butyl) amino) dipropylvinylsilane,
(Dimethylamino) dibutylvinylsilane, (ethylmethylamino) dibutylvinylsilane, (diethylamino) dibutylvinylsilane, (ethyl-n-propylamino) dibutylvinylsilane, (ethylisopropylamino) dibutylvinylsilane, (di (n-propyl) amino) dibutyl Examples include vinyl silane, (diisopropylamino) dibutylvinylsilane, (n-butyl-n-propylamino) dibutylvinylsilane, (di (n-butyl) amino) dibutylvinylsilane, and the like.
{Di (trialkylsilyl) amino} dialkylvinylsilane includes {di (trimethylsilyl) amino} dimethylvinylsilane, {di (t-butyldimethylsilyl) amino} dimethylvinylsilane, {di (trimethylsilyl) amino} diethylvinylsilane, {di And (t-butyldimethylsilyl) amino} diethylvinylsilane.
(Dialkylamino) dialkoxyalkylvinylsilane includes (dimethylamino) dimethoxymethylvinylsilane, (dimethylamino) dimethoxyethylvinylsilane, (dimethylamino) diethoxymethylvinylsilane, (dimethylamino) diethoxyethylvinylsilane, (diethylamino) dimethoxymethyl Examples include vinylsilane, (diethylamino) dimethoxyethylvinylsilane, (diethylamino) diethoxymethylvinylsilane, (diethylamino) diethoxyethylvinylsilane, and the like.

Compounds in which two of X ⁴ , X ⁵ and X ⁶ are acyclic amino groups represented by the formula (IVa) and one is a hydrocarbyl group or a substituted hydrocarbyl group include bis (dialkylamino) alkylvinylsilane, bis { And di (trialkylsilyl) amino} alkylvinylsilane, bis (dialkylamino) alkoxyalkylvinylsilane, and the like.
Bis (dialkylamino) alkylvinylsilanes include bis (dimethylamino) methylvinylsilane, bis (ethylmethylamino) methylvinylsilane, bis (diethylamino) methylvinylsilane, bis (ethyl-n-propylamino) methylvinylsilane, and bis (ethylisopropyl). Amino) methylvinylsilane, bis (di (n-propyl) amino) methylvinylsilane, bis (diisopropylamino) methylvinylsilane, bis (n-butyl-n-propylamino) methylvinylsilane, bis (di (n-butyl) amino) Methyl vinyl silane,
Bis (dimethylamino) ethylvinylsilane, bis (ethylmethylamino) ethylvinylsilane, bis (diethylamino) ethylvinylsilane, bis (ethyl-n-propylamino) ethylvinylsilane, bis (ethylisopropylamino) ethylvinylsilane, bis (di (n -Propyl) amino) ethylvinylsilane, bis (diisopropylamino) ethylvinylsilane, bis (n-butyl-n-propylamino) ethylvinylsilane, bis (di (n-butyl) amino) ethylvinylsilane,
Bis (dimethylamino) propylvinylsilane, bis (ethylmethylamino) propylvinylsilane, bis (diethylamino) propylvinylsilane, bis (ethyl-n-propylamino) propylvinylsilane, bis (ethylisopropylamino) propylvinylsilane, bis (di (n -Propyl) amino) propylvinylsilane, bis (diisopropylamino) propylvinylsilane, bis (n-butyl-n-propylamino) propylvinylsilane, bis (di (n-butyl) amino) propylvinylsilane,
Bis (dimethylamino) butylvinylsilane, bis (ethylmethylamino) butylvinylsilane, bis (diethylamino) butylvinylsilane, bis (ethyl-n-propylamino) butylvinylsilane, bis (ethylisopropylamino) butylvinylsilane, bis (di (n -Propyl) amino) butylvinylsilane, bis (diisopropylamino) butylvinylsilane, bis (n-butyl-n-propylamino) butylvinylsilane, bis (di (n-butyl) amino) butylvinylsilane, and the like.
Examples of bis {di (trialkylsilyl) amino} alkylvinylsilane include bis {di (trimethylsilyl) amino} methylvinylsilane, bis {di (t-butyldimethylsilyl) amino} methylvinylsilane, bis {di (trimethylsilyl) amino} ethyl Examples thereof include vinyl silane and bis {di (t-butyldimethylsilyl) amino} ethyl vinyl silane.
Examples of bis (dialkylamino) alkoxyalkylvinylsilane include bis (dimethylamino) methoxymethylvinylsilane, bis (dimethylamino) methoxyethylvinylsilane, bis (dimethylamino) ethoxymethylvinylsilane, bis (dimethylamino) ethoxyethylvinylsilane,
Examples thereof include bis (diethylamino) methoxymethylvinylsilane, bis (diethylamino) methoxyethylvinylsilane, bis (diethylamino) ethoxymethylvinylsilane, and bis (diethylamino) ethoxyethylvinylsilane.

Examples of the compound in which three of X ⁴ , X ⁵ and X ⁶ are acyclic amino groups represented by the formula (IVa) include tri (dialkylamino) vinylsilane.
For example, tri (dimethylamino) vinylsilane, tri (ethylmethylamino) vinylsilane, tri (diethylamino) vinylsilane, tri (ethylpropylamino) vinylsilane, tri (dipropylamino) vinylsilane, tri (butylpropylamino) vinylsilane Can do.

Compounds in which two of X ⁴ , X ⁵ and X ⁶ are cyclic amino groups represented by the formula (IVa) and one is a hydrocarbyl group or a substituted hydrocarbyl group include bis (morpholino) methylvinylsilane, bis (piperidino) methyl Examples thereof include vinyl silane, bis (4,5-dihydroimidazolyl) methyl vinyl silane, and bis (hexamethyleneimino) methyl vinyl silane.

As the vinyl compound represented by the formula (IV) in which two of X ⁴ , X ⁵ and X ⁶ are groups represented by the formula (IVa), preferably two of X ⁴ , X ⁵ and X ⁶ are acyclic A vinyl compound which is an amino group, and from the viewpoint of low fuel consumption, wet grip performance and wear resistance, more preferably bis (dialkylamino) alkylvinylsilane, and still more preferably bis (dimethylamino) methylvinylsilane, Bis (diethylamino) methylvinylsilane, bis (di (n-propyl) amino) methylvinylsilane, and bis (di (n-butyl) amino) methylvinylsilane. Of these, bis (diethylamino) methylvinylsilane and bis (di (n-butyl) amino) methylvinylsilane are preferable from the viewpoint of availability of the compound.

In (Step A), polymerization may be performed by combining the conjugated diene and the vinyl compound represented by the formula (IV) with another monomer. Other monomers include aromatic vinyl, vinyl nitrile, unsaturated carboxylic acid ester, and the like. Examples of the aromatic vinyl include styrene, α-methylstyrene, vinyl toluene, vinyl naphthalene, divinyl benzene, trivinyl benzene, and divinyl naphthalene. Examples of the vinyl nitrile include acrylonitrile, and examples of the unsaturated carboxylic acid ester include methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate. Among these, aromatic vinyl is preferable, and styrene is more preferable.

Polymerization in (Step A) is an agent that adjusts the vinyl bond amount of the conjugated diene unit, and an agent that adjusts the distribution of constituent units based on monomers other than the conjugated diene unit and the conjugated diene in the conjugated diene polymer chain. (Hereinafter collectively referred to as “regulator”) or the like. Examples of such agents include ether compounds, tertiary amines, and phosphine compounds. Examples of the ether compound include cyclic ethers such as tetrahydrofuran, tetrahydropyran, and 1,4-dioxane; aliphatic monoethers such as diethyl ether and dibutyl ether; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, and diethylene glycol diethyl ether. And aliphatic diethers such as diethylene glycol dibutyl ether; aromatic ethers such as diphenyl ether and anisole. Examples of the tertiary amine include triethylamine, tripropylamine, tributylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N-diethylaniline, pyridine, quinoline and the like. Examples of the phosphine compound include trimethylphosphine, triethylphosphine, triphenylphosphine, and the like. These may be used alone or in combination of two or more.

The polymerization temperature in (Step A) is usually 25 to 100 ° C., preferably 35 to 90 ° C. More preferably, it is 50 to 80 ° C. The polymerization time is usually 10 minutes to 5 hours.

In (Step B), the amount of the compound having a group represented by the formula (II) to be brought into contact with the polymer prepared in Step A is usually 0.1 to 1 per mole of alkali metal derived from the alkali metal catalyst. 3 moles, preferably 0.5 to 2 moles, more preferably 0.7 to 1.5 moles.

In (Step B), the temperature at which the polymer prepared in Step A is brought into contact with the compound having a group represented by the formula (II) is usually 25 to 100 ° C., preferably 35 to 90 ° C. . More preferably, it is 50 to 80 ° C. The contact time is usually 60 seconds to 5 hours, preferably 5 minutes to 1 hour, more preferably 15 minutes to 1 hour.

In the method for producing the conjugated diene polymer, a coupling agent may be added to the hydrocarbon solution of the conjugated diene polymer in the polymerization termination from the start of polymerization of the monomer using an alkali metal catalyst, if necessary. Good. Examples of the coupling agent include compounds represented by the following formula (V).
R ¹² _a ML _4-a (V)
(Wherein R ¹² represents an alkyl group, an alkenyl group, a cycloalkenyl group or an aromatic residue, M represents a silicon atom or a tin atom, L represents a halogen atom or a hydrocarbyloxy group, and a represents 0-2. Represents an integer.)
Here, the aromatic residue represents a monovalent group obtained by removing hydrogen bonded to an aromatic ring from an aromatic hydrocarbon.

As the coupling agent represented by the formula (V), silicon tetrachloride, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, tin tetrachloride, methyltrichlorotin, dimethyldichlorotin, trimethylchlorotin, tetramethoxysilane, methyl Examples include trimethoxysilane, dimethoxydimethylsilane, methyltriethoxysilane, ethyltrimethoxysilane, dimethoxydiethylsilane, diethoxydimethylsilane, tetraethoxysilane, ethyltriethoxysilane, and diethoxydiethylsilane.

The addition amount of the coupling agent is preferably 0.03 mol or more, more preferably 0.05 mol or more, from the viewpoint of processability of the conjugated diene polymer per 1 mol of alkali metal derived from the alkali metal catalyst. is there. Moreover, from a viewpoint of low fuel consumption, Preferably it is 0.4 mol or less, More preferably, it is 0.3 mol or less.

Conjugated diene polymers can be collected by known recovery methods, for example, (1) a method of adding a coagulant to a hydrocarbon solution of a conjugated diene polymer, and (2) adding steam to a hydrocarbon solution of a conjugated diene polymer. By this method, the conjugated diene polymer can be recovered from the hydrocarbon solution. The recovered conjugated diene polymer may be dried by a known dryer such as a band dryer or an extrusion dryer.

Moreover, in the manufacturing method of the said conjugated diene polymer, it is preferable to perform the process which substitutes the group represented by the formula (Ia) of a polymer by a hydroxyl group by hydrolysis etc. The treatment may be performed in the state of the polymer alone or in the state of the composition as described below. Examples of the hydrolysis method include known methods such as a method by steam stripping. The above-described processing, the X ^1, X ² and X ³ of the formula (I) may be a hydroxyl group, fuel economy can be further improved in a balanced wet grip performance and abrasion resistance.

The conjugated diene polymer can be used in the rubber composition of the present invention as a rubber component, and is preferably used in combination with other rubber components and additives.

Examples of other rubber components include conventional styrene-butadiene copolymer rubber, polybutadiene rubber (BR), butadiene-isoprene copolymer rubber, and butyl rubber. In addition, natural rubber (NR), ethylene-propylene copolymer, ethylene-octene copolymer and the like can also be mentioned. Two or more of these rubber components may be used in combination. Especially, it is preferable to use NR and / or BR, and it is more preferable to use both components of NR and BR from the point that low-fuel-consumption property, wet grip performance, and abrasion resistance can be improved with good balance.

The content of the conjugated diene polymer in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 30% by mass or more, and particularly preferably 50% by mass or more. When the content of the conjugated diene polymer is less than 5% by mass, there is a tendency that an improvement effect of low fuel consumption is difficult to obtain. The content of the conjugated diene polymer is preferably 90% by mass or less, more preferably 80% by mass or less, and still more preferably 70% by mass or less. When the content of the conjugated diene polymer exceeds 90% by mass, the wear resistance is lowered and the cost tends to be high.

The NR is not particularly limited. For example, SIR20, RSS # 3, TSR20, deproteinized natural rubber (DPNR), high-purity natural rubber (HPNR), etc., which are common in the tire industry can be used.

The content of NR in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more. If it is less than 5% by mass, the wear resistance tends to decrease. The NR content is preferably 70% by mass or less, more preferably 60% by mass or less. If it exceeds 70% by mass, the wet grip performance tends to decrease.

The BR is not particularly limited. For example, BR1220 manufactured by Nippon Zeon Co., Ltd., BR130B manufactured by Ube Industries, Ltd., BR150B having a high cis content such as BR150B, VCR412 manufactured by Ube Industries, Ltd. Commonly used in the tire industry, such as BR containing syndiotactic polybutadiene crystals, can be used.

The content of BR in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more. If it is less than 5% by mass, the wear resistance tends to decrease. The BR content is preferably 60% by mass or less, more preferably 50% by mass or less, still more preferably 35% by mass or less, and particularly preferably 25% by mass or less. If it exceeds 60% by mass, the wet grip performance tends to decrease.

The total content of NR and BR in 100% by mass of the rubber component is preferably 10% by mass or more, more preferably 20% by mass or more, and further preferably 30% by mass or more. If it is less than 10% by mass, the wear resistance tends to decrease. The total content is preferably 70% by mass or less, more preferably 50% by mass or less. If it exceeds 70% by mass, the wet grip performance tends to decrease.

The rubber composition of the present invention is characterized by compounding silica as a reinforcing agent. The compounding amount (content) of the silica is preferably 5 to 150 parts by mass, more preferably 10 to 100 parts by mass with respect to 100 parts by mass of the rubber component. When the amount of silica is less than 5 parts by mass, the wear resistance tends to be insufficient, while when the amount of silica exceeds 150 parts by mass, the workability tends to deteriorate. Silica may be used alone or in combination of two or more.

The nitrogen adsorption specific surface area (N ₂ SA) of the silica is preferably 40 to 400 m ² / g, and more preferably 60 to 360 m ² / g. Silica having a nitrogen adsorption specific surface area of less than 40 m ² / g has a small reinforcing effect and tends to have low wear resistance, and silica having a nitrogen adsorption specific surface area of more than 400 m ² / g has poor dispersibility, increases hysteresis loss, and lowers fuel efficiency. Tend to.
Note that the nitrogen adsorption specific surface area of silica is a value measured by the BET method according to ASTM D3037-81.

The content of silica in a total of 100% by mass of silica and carbon black is preferably 60% by mass or more, more preferably 85% by mass or more, preferably 98% by mass or less, more preferably 95% by mass or less. . If it is in the said range, low-fuel-consumption property, wet-grip performance, and abrasion resistance can be improved with a high dimension in a well-balanced manner.

A silane coupling agent may be used in combination with the silica. Examples of silane coupling agents include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, and bis (2-triethoxy). Silylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyl Trimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarb Moyl tetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilyl Propyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis (3-diethoxymethylsilylpropyl) tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide And dimethoxymethylsilylpropylbenzothiazole tetrasulfide. Of these, bis (3-triethoxysilylpropyl) tetrasulfide and 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide are preferable from the viewpoint of improving reinforcing properties. These silane coupling agents may be used alone or in combination of two or more.

The compounding amount of the silane coupling agent is preferably 1 part by mass or more and more preferably 2 parts by mass or more with respect to 100 parts by mass of the silica. If the compounding amount of the silane coupling agent is less than 1 part by mass, the viscosity of the unvulcanized rubber composition tends to be high and the processability tends to be poor. Moreover, it is preferable that it is 20 mass parts or less with respect to 100 mass parts of said silica, and, as for the compounding quantity of a silane coupling agent, it is more preferable that it is 15 mass parts or less. When the compounding quantity of a silane coupling agent exceeds 20 mass parts, the compounding effect of the silane coupling agent as the compounding quantity will not be acquired, and there exists a tendency for cost to become high.

Known additives can be used, such as sulfur vulcanizing agents; thiazole vulcanization accelerators, thiuram vulcanization accelerators, sulfenamide vulcanization accelerators, guanidine vulcanization accelerators. Vulcanization accelerators such as stearic acid and zinc oxide; organic peroxides; fillers such as carbon black, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica; silane coupling Agents; processing aids such as extender oils and lubricants; anti-aging agents can be exemplified.

Examples of the carbon black include furnace black (furness carbon black) such as SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF and ECF; acetylene black (acetylene carbon black); FT and Examples thereof include thermal black (thermal carbon black) such as MT; channel black (channel carbon black) such as EPC, MPC and CC; graphite. These can be used alone or in combination of two or more. The content of carbon black is preferably 1 part by mass or more, more preferably 3 parts per 100 parts by mass of the rubber component from the viewpoint that fuel economy, wet grip performance and wear resistance can be improved in a high-dimensional and well-balanced manner. It is at least part by mass, preferably at most 30 parts by mass, more preferably at most 10 parts by mass.

Nitrogen adsorption specific surface area _(N 2 SA) of carbon black is usually 5 ~ 200m ² / g, the lower limit is preferably ^{50 m} 2 / g, the upper limit is 150 meters ² / g. Carbon black has a dibutyl phthalate (DBP) absorption of usually 5 to 300 ml / 100 g, preferably a lower limit of 80 ml / 100 g and an upper limit of 180 ml / 100 g. If the N ₂ SA or DBP absorption amount of the carbon black is less than the lower limit of the above range, the reinforcing effect tends to be small and the wear resistance tends to decrease. If the upper limit of the above range is exceeded, dispersibility is poor and hysteresis loss increases. There is a tendency for fuel efficiency to decrease. The nitrogen adsorption specific surface area is measured according to ASTM D4820-93, and the DBP absorption is measured according to ASTM D2414-93. As a commercial item, Tokai Carbon Co., Ltd. product name Siest 6 and Siest 7HM, Sieast KH, the product name CK3 by Degussa, Special Black 4A, etc. can be used.

Examples of the extending oil include aromatic mineral oil (viscosity specific gravity constant (VGC value) 0.900 to 1.049), naphthenic mineral oil (VGC value 0.850 to 0.899), paraffinic mineral oil (VGC value 0.790 to 0.849), and the like. The polycyclic aromatic content of the extender oil is preferably less than 3% by mass, more preferably less than 1% by mass. The polycyclic aromatic content is measured according to the British Petroleum Institute 346/92 method. Moreover, the aromatic compound content (CA) of the extending oil is preferably 20% by mass or more. These extending oils may be used in combination of two or more.

Examples of the vulcanization accelerator include thiazole vulcanization accelerators such as 2-mercaptobenzothiazole, dibenzothiazyl disulfide, and N-cyclohexyl-2-benzothiazylsulfenamide; tetramethylthiuram monosulfide, tetramethylthiuram Thiuram vulcanization accelerators such as disulfides; N-cyclohexyl-2-benzothiazole sulfenamide, Nt-butyl-2-benzothiazole sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, N -Sulfenamide vulcanization accelerators such as oxyethylene-2-benzothiazole sulfenamide, N, N'-diisopropyl-2-benzothiazole sulfenamide; diphenylguanidine, diortolylguanidine, orthotolylbiguanidine, etc. No Mention may be made of bleeding based vulcanization accelerator, its amount is preferably from 0.1 to 5 parts by mass with respect to 100 parts by mass of the rubber component, more preferably 0.2 to 3 parts by weight.

As a method for producing a rubber composition by blending the conjugated diene polymer with other rubber components or additives, a known method, for example, using a known mixer such as a roll or a banbury for each component. A kneading method can be used.

As the kneading conditions, when additives other than the vulcanizing agent and the vulcanization accelerator are blended, the kneading temperature is usually 50 to 200 ° C., preferably 80 to 190 ° C., and the kneading time is usually 30 seconds. -30 minutes, and preferably 1-30 minutes.
When a vulcanizing agent and a vulcanization accelerator are blended, the kneading temperature is usually 100 ° C. or lower, preferably room temperature to 80 ° C. A composition containing a vulcanizing agent and a vulcanization accelerator is usually used after vulcanization treatment such as press vulcanization. The vulcanization temperature is usually 120 to 200 ° C, preferably 140 to 180 ° C.

The rubber composition of the present invention is excellent in the balance of low fuel consumption, wet grip performance and wear resistance, and can achieve a remarkable improvement effect of these performances.

The rubber composition of the present invention can be suitably used for each member of a tire, and can be particularly suitably used for a tread.

The pneumatic tire of the present invention is produced by a usual method using the rubber composition. That is, a rubber composition containing various additives as necessary is extruded in accordance with the shape of the tread of the tire at an unvulcanized stage, molded by a normal method on a tire molding machine, etc. The tire members are bonded together to form an unvulcanized tire. This unvulcanized tire can be heated and pressurized in a vulcanizer to produce the pneumatic tire of the present invention.

The pneumatic tire of the present invention can be suitably used as a tire for passenger cars and a tire for trucks and buses (heavy load tire).

Hereinafter, the present invention will be described by way of examples.
The physical properties were evaluated by the following method. In the following evaluation, Examples 1 to 5 and Comparative Examples 2 to 4 used Comparative Example 1 as a reference comparative example, and Example 6 used Comparative Example 5 as a reference comparative example.

1. Vinyl bond amount (unit: mol%)
The amount of vinyl bonds in the polymer was determined from the absorption intensity near 910 cm ^−1, which is the absorption peak of the vinyl group, by infrared spectroscopy.

2. Styrene unit content (unit: mass%)
According to JIS K6383 (1995), the content of styrene units in the polymer was determined from the refractive index.

3. Molecular weight distribution (Mw / Mn)
The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) method under the following conditions (1) to (8). And the molecular weight distribution (Mw / Mn) of the polymer was calculated | required from measured Mw and Mn.
(1) Equipment: HLC-8020 manufactured by Tosoh Corporation
(2) Separation column: GMH-XL (two in series) manufactured by Tosoh Corporation
(3) Measurement temperature: 40 ° C
(4) Carrier: Tetrahydrofuran (5) Flow rate: 0.6 mL / min (6) Injection volume: 5 μL
(7) Detector: Differential refraction (8) Molecular weight standard: Standard polystyrene

4). tan δ
A strip-shaped test piece having a width of 1 mm or 2 mm and a length of 40 mm was punched out of the sheet-like vulcanized rubber composition and subjected to the test. Using a spectrometer manufactured by Ueshima Seisakusho, tan δ was measured at a dynamic strain amplitude of 1%, a frequency of 10 Hz, and a temperature of 50 ° C. The reciprocal value of tan δ was expressed as an index with the reference comparative example being 100. The larger the value, the lower the rolling resistance and the lower the fuel consumption.

5. Rolling resistance Using a rolling resistance tester, measure the rolling resistance when the test tire was run at a rim (15 × 6JJ), internal pressure (230 kPa), load (3.43 kN), speed (80 km / h). Indicated as an index when the reference comparative example is 100. A larger index is better (low fuel consumption).

6). Wet grip performance Each test tire was mounted on all wheels of a vehicle (domestic FF2000cc), and a braking distance from an initial speed of 100 km / h was determined on a wet asphalt road surface. The result is expressed as an index. The larger the number, the better the wet skid performance (wet grip performance). The index was calculated by the following formula.
Wet skid performance = (braking distance of reference comparative example) / (braking distance of each example or comparative example) × 100

7. LAT abrasion test Using a LAT tester (Laboratory Abrasion and Skid Tester), the volume loss of each vulcanized rubber composition was measured under the conditions of a load of 50 N, a speed of 20 km / h, and a slip angle of 5 °. The numerical values (LAT index) in Tables 2 and 3 are relative values when the volume loss amount of the reference comparative example is 100. The larger the value, the better the wear resistance.

Production Example 1 (Synthesis of Polymer 1)
5. The inside of a stainless steel polymerization reactor having an internal volume of 20 liters was washed, dried, and replaced with dry nitrogen, and hexane (specific gravity 0.68 g / cm ³ ) 10.2 kg, 1,3-butadiene 547 g, styrene 173 g, tetrahydrofuran 6. 1 ml and ethylene glycol diethyl ether 5.0 ml were charged into the polymerization reactor. Next, 11.5 mmol of bis (diethylamino) methylvinylsilane and 14.1 mmol of n-butyllithium were added as a cyclohexane solution and an n-hexane solution, respectively, to initiate polymerization.
While the stirring speed was 130 rpm, the temperature in the polymerization reactor was 65 ° C., 1,3-butadiene and styrene were copolymerized for 3 hours while continuously supplying the monomer into the polymerization reactor. The amount of 1,3-butadiene supplied in the entire polymerization was 821 g, and the amount of styrene supplied was 259 g.
Next, the obtained polymer solution was stirred at a stirring speed of 130 rpm, 11.5 mmol of N, N-dimethylformamide dimethyl acetal was added, and the mixture was stirred for 15 minutes. 20 ml of hexane solution containing 0.54 ml of methanol was added to the polymer solution, and the polymer solution was further stirred for 5 minutes.

2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilyzer GM) was added to the polymer solution. 8 g, 0.9 g of pentaerythrityl tetrakis (3-lauryl thiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Smither TP-D) was added, and then the polymer was removed from the polymer solution by steam stripping. 1 was recovered. The evaluation results of the polymer 1 are shown in Table 1. In addition, the content of the structural unit represented by the formula (I) in the polymer calculated from the input amount and the supply amount of the raw material into the polymerization reactor is 0.006 mmol / g polymer per polymer unit mass. there were.

Production Example 2 (Synthesis of Polymer 2)
5. The inside of a stainless steel polymerization reactor having an internal volume of 20 liters was washed, dried, and replaced with dry nitrogen, and hexane (specific gravity 0.68 g / cm ³ ) 10.2 kg, 1,3-butadiene 547 g, styrene 173 g, tetrahydrofuran 6. 1 ml and ethylene glycol diethyl ether 5.0 ml were charged into the polymerization reactor. Next, 14.1 mmol of n-butyllithium was added as an n-hexane solution, and 1,3-butadiene and styrene were copolymerized for 1 hour. During the polymerization, the stirring speed was 130 rpm, the temperature in the polymerization reactor was 65 ° C., and the monomer was continuously fed into the polymerization reactor.
After the polymerization for 1 hour, 11.0 mmol of bis (diethylamino) methylvinylsilane was added as a cyclohexane solution, and the mixture was charged into the polymerization reactor under the conditions of a stirring speed of 130 rpm and a polymerization reactor temperature of 65 ° C.
Next, the monomer was continuously fed into the polymerization reactor, and 1,3-butadiene and styrene were copolymerized for 0.5 hour. During the polymerization, the stirring speed was 130 rpm, and the temperature in the polymerization reactor was 65 ° C.
After the 0.5 hour polymerization, 11.0 mmol of bis (diethylamino) methylvinylsilane was added as a cyclohexane solution, and the mixture was charged into the polymerization reactor under the conditions of a stirring speed of 130 rpm and a polymerization reactor internal temperature of 65 ° C.
Next, the monomer was continuously fed into the polymerization reactor, and 1,3-butadiene and styrene were copolymerized for 0.5 hour. During the polymerization, the stirring speed was 130 rpm, and the temperature in the polymerization reactor was 65 ° C.
After the 0.5 hour polymerization, 11.0 mmol of bis (diethylamino) methylvinylsilane was added as a cyclohexane solution, and the mixture was charged into the polymerization reactor under the conditions of a stirring speed of 130 rpm and a polymerization reactor internal temperature of 65 ° C.
Next, the monomer was continuously fed into the polymerization reactor, and 1,3-butadiene and styrene were copolymerized for 0.5 hour. During the polymerization, the stirring speed was 130 rpm, and the temperature in the polymerization reactor was 65 ° C. The amount of 1,3-butadiene supplied in the entire polymerization was 821 g, and the amount of styrene supplied was 259 g.
Next, the obtained polymer solution was stirred at a stirring speed of 130 rpm, 11.0 mmol of N, N-dimethylformamide dimethylacetal was added, and the mixture was stirred for 15 minutes. 20 ml of hexane solution containing 0.54 ml of methanol was added to the polymer solution, and the polymer solution was further stirred for 5 minutes.

2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilyzer GM) was added to the polymer solution. 8 g, 0.9 g of pentaerythrityl tetrakis (3-lauryl thiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Smither TP-D) was added, and then the polymer was removed from the polymer solution by steam stripping. 2 was recovered. The evaluation results of Polymer 2 are shown in Table 1. In addition, the content of the structural unit represented by the formula (I) in the polymer calculated from the input amount and the supply amount of the raw material into the polymerization reactor is 0.018 mmol / g polymer per polymer unit mass. there were.

Production Example 3 (Synthesis of Polymer 3)
The inside of a stainless steel polymerization reactor having an internal volume of 5 liters was washed, dried, and replaced with dry nitrogen, 2.55 kg of hexane (specific gravity 0.68 g / cm ³ ) 2.53 kg, 1,3-butadiene 137 g, styrene 43 g, tetrahydrofuran 1. 5 ml and 1.2 ml of ethylene glycol diethyl ether were charged into the polymerization reactor. Next, 3.6 mmol of n-butyllithium was added as an n-hexane solution, and 1,3-butadiene and styrene were copolymerized for 2.5 hours. During the polymerization, the stirring speed was 130 rpm, the temperature in the polymerization reactor was 65 ° C., and the monomer was continuously fed into the polymerization reactor. The amount of 1,3-butadiene supplied was 205 g, and the amount of styrene supplied was 65 g.
After the polymerization for 2.5 hours, 2.8 mmol of bis (diethylamino) methylvinylsilane as a cyclohexane solution was added into the polymerization reactor under a stirring speed of 130 rpm and a polymerization reactor internal temperature of 65 ° C. and stirred for 30 minutes. . Next, 20 ml of a hexane solution containing 0.14 ml of methanol was put into the polymerization reactor, and the polymer solution was stirred for 5 minutes.

2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilyzer GM) was added to the polymer solution. 8 g, 0.9 g of pentaerythrityl tetrakis (3-lauryl thiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Smither TP-D) was added, and then the polymer was removed from the polymer solution by steam stripping. 3 was recovered. The evaluation results of the polymer 3 are shown in Table 1. In addition, the content of the structural unit represented by the formula (I) in the polymer calculated from the input amount and the supply amount of the raw material into the polymerization reactor is 0.006 mmol / g polymer per polymer unit mass. there were.

Production Example 4 (Synthesis of Polymer 4)
5. The inside of a stainless steel polymerization reactor having an internal volume of 20 liters was washed, dried, and replaced with dry nitrogen, and hexane (specific gravity 0.68 g / cm ³ ) 10.2 kg, 1,3-butadiene 547 g, styrene 173 g, tetrahydrofuran 6. 1 ml and ethylene glycol diethyl ether 5.0 ml were charged into the polymerization reactor. Next, 11.5 mmol of bis (diethylamino) methylvinylsilane and 14.1 mmol of n-butyllithium were added as a cyclohexane solution and an n-hexane solution, respectively, to initiate polymerization.
While the stirring speed was 130 rpm, the temperature in the polymerization reactor was 65 ° C., 1,3-butadiene and styrene were copolymerized for 3 hours while continuously supplying the monomer into the polymerization reactor. The amount of 1,3-butadiene supplied in the entire polymerization was 821 g, and the amount of styrene supplied was 259 g.
Next, 20 ml of hexane solution containing 0.54 ml of methanol was added to the polymer solution, and the polymer solution was further stirred for 5 minutes.

2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilyzer GM) was added to the polymer solution. 8 g, 0.9 g of pentaerythrityl tetrakis (3-lauryl thiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Smither TP-D) was added, and then the polymer was removed from the polymer solution by steam stripping. 4 was recovered. The evaluation results of the polymer 4 are shown in Table 1. In addition, the content of the structural unit represented by the formula (I) in the polymer calculated from the input amount and the supply amount of the raw material into the polymerization reactor is 0.006 mmol / g polymer per polymer unit mass. there were.

Production Example 5 (Synthesis of Polymer 5)
5. The inside of a stainless steel polymerization reactor having an internal volume of 20 liters was washed, dried, and replaced with dry nitrogen, and hexane (specific gravity 0.68 g / cm ³ ) 10.2 kg, 1,3-butadiene 547 g, styrene 173 g, tetrahydrofuran 6. 1 ml and ethylene glycol diethyl ether 5.0 ml were charged into the polymerization reactor. Next, 14.1 mmol of n-butyllithium was added as an n-hexane solution to initiate polymerization.
While the stirring speed was 130 rpm, the temperature in the polymerization reactor was 65 ° C., 1,3-butadiene and styrene were copolymerized for 3 hours while continuously supplying the monomer into the polymerization reactor. The amount of 1,3-butadiene supplied in the entire polymerization was 821 g, and the amount of styrene supplied was 259 g.
Next, the obtained polymer solution was stirred at a stirring speed of 130 rpm, 11.5 mmol of N, N-dimethylformamide dimethyl acetal was added, and the mixture was stirred for 15 minutes. 20 ml of hexane solution containing 0.54 ml of methanol was added to the polymer solution, and the polymer solution was further stirred for 5 minutes.

2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilyzer GM) was added to the polymer solution. 8 g, 0.9 g of pentaerythrityl tetrakis (3-lauryl thiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Smither TP-D) was added, and then the polymer was removed from the polymer solution by steam stripping. 5 was recovered. The evaluation results of the polymer 5 are shown in Table 1. In addition, since the polymer 5 did not use the compound represented by Formula (IV) at the time of a synthesis | combination, it did not contain the structural unit represented by Formula (I).

Production Example 6 (Synthesis of Polymer 6)
5. The inside of a stainless steel polymerization reactor having an internal volume of 20 liters was washed, dried, and replaced with dry nitrogen, and hexane (specific gravity 0.68 g / cm ³ ) 10.2 kg, 1,3-butadiene 547 g, styrene 173 g, tetrahydrofuran 6. 1 ml and ethylene glycol diethyl ether 5.0 ml were charged into the polymerization reactor. Next, 14.1 mmol of n-butyllithium was added as an n-hexane solution to initiate polymerization.
While the stirring speed was 130 rpm, the temperature in the polymerization reactor was 65 ° C., 1,3-butadiene and styrene were copolymerized for 3 hours while continuously supplying the monomer into the polymerization reactor. The amount of 1,3-butadiene supplied in the entire polymerization was 821 g, and the amount of styrene supplied was 259 g.
Next, 20 ml of hexane solution containing 0.54 ml of methanol was added to the polymer solution, and the polymer solution was further stirred for 5 minutes.

2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilyzer GM) was added to the polymer solution. 8 g, 0.9 g of pentaerythrityl tetrakis (3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) was added, and then the polymer was removed from the polymer solution by steam stripping. 6 was recovered. The evaluation results of the polymer 6 are shown in Table 1. In addition, since the polymer 6 did not use the compound represented by Formula (IV) at the time of a synthesis | combination, it did not contain the structural unit represented by Formula (I).

Production Example 7 (Synthesis of Polymer 7)
5. The inside of a stainless steel polymerization reactor having an internal volume of 20 liters was washed, dried, and replaced with dry nitrogen, and hexane (specific gravity 0.68 g / cm ³ ) 10.2 kg, 1,3-butadiene 547 g, styrene 173 g, tetrahydrofuran 6. 1 ml and ethylene glycol diethyl ether 5.0 ml were charged into the polymerization reactor. Next, 11.5 mmol of bis (diethylamino) methylvinylsilane and 14.1 mmol of n-butyllithium were added as a cyclohexane solution and an n-hexane solution, respectively, to initiate polymerization.
While the stirring speed was 130 rpm, the temperature in the polymerization reactor was 65 ° C., 1,3-butadiene and styrene were copolymerized for 3 hours while continuously supplying the monomer into the polymerization reactor. The amount of 1,3-butadiene supplied in the entire polymerization was 821 g, and the amount of styrene supplied was 259 g.
Next, the obtained polymer solution was stirred at a stirring speed of 130 rpm, 11.5 mmol of N, N-dimethylformamide dimethyl acetal was added, and the mixture was stirred for 15 minutes. 20 ml of hexane solution containing 0.54 ml of methanol was added to the polymer solution, and the polymer solution was further stirred for 5 minutes.

2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilyzer GM) was added to the polymer solution. 8 g, 0.9 g of pentaerythrityl tetrakis (3-lauryl thiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilyzer TP-D) was added, and then the polymer solution was added at room temperature for 24 hours. Evaporated and further dried under reduced pressure at 55 ° C. for 12 hours to obtain a polymer 7. The evaluation results of the polymer 7 are shown in Table 1. In addition, the content of the structural unit represented by the formula (I) in the polymer calculated from the input amount and the supply amount of the raw material into the polymerization reactor is 0.006 mmol / g polymer per polymer unit mass. there were.

Below, various chemical | medical agents used by the Example and the comparative example are demonstrated.
Natural rubber: RSS # 3
Butadiene rubber: Ubepol BR150B manufactured by Ube Industries, Ltd.
Polymers 1 to 7: Production Examples 1 to 7 above
Silica: Ultrasil VN3-G manufactured by Degussa (N ₂ SA: 175 m ² / g)
Silane coupling agent: Si69 (bis (3-triethoxysilylpropyl) tetrasulfide) manufactured by Degussa
Carbon black: Dia Black N339 manufactured by Mitsubishi Chemical Corporation (N ₂ SA: 96 m ² / g, DBP absorption: 124 ml / 100 g)
Oil: X-140 manufactured by Japan Energy Co., Ltd.
Anti-aging agent: Antigen 3C manufactured by Sumitomo Chemical Co., Ltd.
Stearic acid: Beads manufactured by NOF Corporation Zinc stearate Zinc oxide: Zinc flower No. 1 manufactured by Mitsui Kinzoku Mining Co., Ltd. Wax: Sunnock N manufactured by Ouchi Shinsei Chemical Co., Ltd.
Sulfur: Powder sulfur vulcanization accelerator manufactured by Tsurumi Chemical Industry Co., Ltd. 1: Soxinol CZ manufactured by Sumitomo Chemical Co., Ltd.
Vulcanization accelerator 2: Soxinol D manufactured by Sumitomo Chemical Co., Ltd.

(Examples 1 to 6 and Comparative Examples 1 to 5)
In accordance with the contents shown in Tables 2 and 3, materials other than sulfur and a vulcanization accelerator were kneaded for 5 minutes at 150 ° C. using a 1.7 L Banbury mixer manufactured by Kobe Steel, Ltd., and mixed. A kneaded paste was obtained. Next, sulfur and a vulcanization accelerator were added to the obtained kneaded product, and kneaded for 5 minutes under the condition of 80 ° C. using an open roll to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition was press vulcanized with a 0.5 mm thick mold at 170 ° C. for 20 minutes to obtain a vulcanized rubber composition.
Further, the obtained unvulcanized rubber composition is molded into a tread shape and bonded together with other tire members on a tire molding machine to form an unvulcanized tire, which is vulcanized at 170 ° C. for 12 minutes, and tested. Tires (size: 195 / 65R15) were manufactured.

The obtained vulcanized rubber composition and test tire were used for evaluation by the above test method. The test results are shown in Tables 2 and 3.

As shown in Tables 2 and 3, the terminal is modified by a compound having a structural unit based on a conjugated diene and a structural unit represented by the above formula (I) and having a group represented by the above formula (II). The rubber compositions of Examples including the prepared polymers (Polymers 1, 2, and 7) have improved fuel economy, wet grip performance, and wear resistance in a well-balanced manner as compared with the rubber compositions of Comparative Examples. It was.

Claims

Containing a rubber component and silica,
A conjugated diene-based polymer having a structural unit based on a conjugated diene and a structural unit represented by the following formula (I) in 100% by mass of the rubber component, wherein the group represented by the following formula (II): The content of the conjugated diene polymer obtained by modifying at least one end of the polymer with the compound having 5% by mass or more,
A rubber composition, wherein the content of the silica is 5 to 150 parts by mass with respect to 100 parts by mass of the rubber component.

[Wherein, X 1 , X 2 and X 3 each independently represent a group represented by the following formula (Ia), a hydroxyl group, a hydrocarbyl group or a substituted hydrocarbyl group, and at least one of X 1 , X 2 and X 3 One is a group or a hydroxyl group represented by the following formula (Ia). ]

[Wherein, R 1 and R 2 each independently represent a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having a carbon number of 1-6, a silyl group, or a substituted silyl group, R 1 and R 2 may be bonded to form a ring structure with the nitrogen atom. ]

[Wherein, m represents an integer of 1 to 11, and A represents a functional group having a nitrogen atom. ]
The rubber composition according to claim 1, wherein R 1 and R 2 in the formula (Ia) are hydrocarbyl groups having 1 to 6 carbon atoms.
The rubber composition according to claim 1 or 2, wherein two of X 1 , X 2 and X 3 in the formula (I) are a group or a hydroxyl group represented by the formula (Ia).
The rubber composition according to any one of claims 1 to 3, wherein the compound having a group represented by the formula (II) is a compound represented by the following formula (III).

[Wherein n represents an integer of 0 to 10, R 3 represents a hydrocarbyl group having 1 to 5 carbon atoms, and R 4 , R 5 , R 6 and R 7 each independently represents a hydrogen atom, A hydrocarbyl group having 1 to 5 carbon atoms, a substituted hydrocarbyl group having 1 to 5 carbon atoms, or a hydrocarbyloxy group having 1 to 5 carbon atoms, and a plurality of R 4 and R 5 are present. R 4 and a plurality of R 5 may be the same or different, and R 8 and R 9 are each independently at least one selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. Represents a group having 1 to 6 carbon atoms which may have an atom, R 8 and R 9 may combine to form a ring structure with a nitrogen atom, and R 8 and R 9 It may be the same group bonded by a double bond ]
One of R < 6 > and R < 7 > of Formula (III) is a hydrogen atom, The rubber composition of Claim 4 characterized by the above-mentioned.
The vinyl bond amount of the conjugated diene polymer is 10 mol% or more and 80 mol% or less, where the content of the constituent unit based on the conjugated diene is 100 mol%. The rubber composition as described.
The rubber composition according to any one of claims 1 to 6, which contains natural rubber and / or butadiene rubber.
The rubber composition according to any one of claims 1 to 7, wherein the silica has a nitrogen adsorption specific surface area of 40 to 400 m 2 / g.
The rubber composition according to any one of claims 1 to 8, which is used as a rubber composition for a tread.
A pneumatic tire produced using the rubber composition according to any one of claims 1 to 9.